HI Bob
Thanks for the update. Sorry to put you to the trouble. I never want to
miss a Rebel meeting, but, I did not want to miss a long paid business
flight. I can claim mileage so to speak.
It is hard to believe that an extra 6.7% power output of the 160 HP Lyc. vs.
150 HP can/is causing this cracking in the Warp Drive blades. I am not
doubting your comments. But it makes me concerned that by adding just this
small amount of power, the blades are cracking. Which indicates that the
blades are operating way too close to failure mode. Not a good thing
knowing what the outcome of an inflight blade separation can cause.
If the solution is to add a flywheel of this weight, I would have gone
straight to the Sensenich prop right off the bat. I wanted the Warp drive
only to get the weight of the nose. I am very happy with the performance of
the Warp Drive, but, if failure is in my future, I better get it off the
airplane.
Thanks for the update.
Best Regards
Brian #328R
-----Original Message-----
From: Bob Patterson [mailto:
bob.patterson@canrem.com]
Sent: Wednesday, October 11, 2000 2:57 PM
To: Murphy Rebel Builders List
Subject: RE: SR engines?
Hi Brian !
We missed you at the meeting ! Everyone enjoys the opportunity
to see your Rebel and gather photos of some of your unique ideas ...
We have added a few new builders or prospects each meeting.
Anna didn't mention she'd spoken to you until later in the
evening - sounds like you had an exciting trip, and are getting some
real business use out of the Rebel !
I'll go from memory (never good ;-) ) on Jack's prop problems.
It seems they found TWO blades with cracks - one was in the blade,
about an inch long, just outside of the collar at the root. The other
was actually IN the aluminum collar section, apparently. Warp Drive
again showed that they have EXCELLENT customer support, by sending
replacements within a few days ! The cracks were found on different
dates, not both at the same time.
This problem is now well known, and so far, has ONLY appeared
on the 160 hp. versions of the O-320 - NO PROBLEMS with the 150 hp.'s.
It seems to be caused by the stronger power pulses, and the changes
they make in the overall harmonic balance of the engine & prop.
One cure that is working (so far), is to add a harmonic balancer
to the flywheel (8 to 15 lb.... varies). This acts to dampen the
pulses and smooth the engine - only a few in use so far ...
There have been a very few scattered reports of blade cracks
on OTHER types of engines - Continental IO-240, etc. These engines
may also have lightweight flywheels that don't sufficiently smooth
the power pulses. The cracking problems are only showing up now
with the lightweight composite props, as the old metal Sensenich &
McCauley props were heavy enough themselves to provide the
flywheel effect.
Next Rebel Builders of Ontario meeting is Sunday, Nov. 12th,
at 1 pm., at the RAA clubhouse at the north end of Brampton Airport
(CNC3). Everyone welcome, as usual !! Hope to see you there !!
......bobp
-----------------------------orig.-------------------------------------
At 10:50 PM 10/10/00 -0400, you wrote:
Hi Bob
Sorry I had to miss the last Rebel meeting. I saw Anna just before I left
that Sunday of the meeting. Had to fly to Indianpolis. It was a really
windy day. Only made 90 KIAS ground speed.
Nice flight i.e. excellent weather & viz. but made me late getting in to
Indy's Class C airspace in the pitch dark. It was hard to find the airport
amongst the city lights.
I would like to hear about Jack Wiebe's prop problem. I have ascertained
that he had a problem with his Warp drive. He called me but by the time I
called him back the next day, he was gone.
Any news?
Regards
Brian #328R
BTW When is the next meeting?
-----Original Message-----
From: Bob Patterson [mailto:
bob.patterson@canrem.com]
Sent: Monday, October 09, 2000 10:12 PM
To: Murphy Rebel Builders List
Subject: RE: SR engines?
Hi Brian !
You're not alone in wanting a six-cylinder Rotax ....
Unfortunately, they targetted their design TOO specifically, without
thought for expansion - the exhaust ports are front & back ! If they'd
put them on the bottom, it would have been easy to just add another
row ....
Too bad, because a 6 would be much smoother running than a
4, and a 150 hp 912-6 would have a GREAT power/weight ratio !
(Of course, they ARE working on a six, but it's in the
300 hp. range, a V configuration, and not related to the 912 in
ANY way ) ..... { this is the <worst-kept> secret in aviation } :-)
As for Zoche - welllll, they're good for a chuckle, I suppose.
Wonder what they're REALLY up to ???!!!
.....bobp
------------------------------orig.---------------------------------------
At 01:27 PM 10/9/00 -0400, you wrote:
Hi Bob
I agree with you. I bet the 912S would be a fabulous replacement for the
Lyc. 0235. The performance would be terrific considering the weight loss.
If only Rotax would build a 6 cylinder @ 150 HP, they would have an
unbelievable combination. It would be 100 lb. less than an 0320 &
considerable better on fuel etc.
They could probably build this faster than Zoche will build their 150 HP/
185 lb. radial marvel. But that is another story.
Cheers as Alister would say
Brian #328R
-----Original Message-----
From: Bob Patterson [mailto:
bob.patterson@canrem.com]
Sent: Sunday, October 08, 2000 11:18 PM
To: Murphy Rebel Builders List
Subject: RE: SR engines?
Ok !! OK !! ;-) It's just an old "guide" - meaning, if you lighten
the aircraft by 100 lb., it will give you approx. the same performance
improvement as adding 10 hp. :-) :-)
I sometimes get my tongue over my eye tooth, and can't see what I'm
saying !! ;-) :-) (Who, me - Wix my Mords ??!! :-) )
That's why I always felt that tossing my old Lycoming O-235C-2C
and installing a Rotax 912-S would probably give me BETTER performance !
The old Lyc. was probably only putting out 100 hp, same as the 912-S,
and the whole installation would have been about 200 lb. lighter !!
This should have resulted in about the performance of a 120 hp. Lyc.
powered Rebel ...
......bobp
----------------------------------orig.-----------------------------------
-
-
At 10:57 PM 10/8/00 -0400, you wrote:
Hi Bob
Per your rule of thumb, a 150 HP engine would weigh 1500 lbs. That would
not leave a lot of room for fuel! I must have you rule of thumb a little
mixed up.
Brian #328R
-----Original Message-----
From: Bob Patterson [mailto:
bob.patterson@canrem.com]
Sent: Sunday, October 08, 2000 10:47 PM
To: Murphy Rebel Builders List
Subject: Re: SR engines?
Hi David !
THAT <IS> impressive !!! Are these weights inclusive of all
(identical) accessories ??? If so, the lighter weight will really
help !!! (Old 'rule of thumb' -> 100 lb of weight ~= 10 hp. !!)
That would give the Franklin the equivalent of 228 hp ...
.....bobp
---------------------------------orig.-----------------------------------
At 07:53 AM 10/6/00 -0400, you wrote:
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